TREX 450 Pro APM/FPV build update 2

add band-aid over barometer. to smooth the pressure differential/buffeting. Makes APM more stable in auto and loiter.

wire and mount 5V power supply (BEC). For discreet power for APM and 433Mhz rx and to prevent brownouts due to servo electrical draw. I’m using digital servos, that have a lot of current draw. These can pull up to 1A each, and I have 4 of those and also need enough power for the APM, receiver, minimosd and telemetry. It’s going to be around 5A to 8A RMS draw on the BEC depending on how its flying. Since I am not using a 3DR power module and I also need more amps on the BEC than the standard 5 amps the Castle ICE 50 provides, I will be adding a external BEC that gives 10A. Normally you cannot parallel BEC’s, but the Castle’s you can, so I can get up to 15A of total BEC 5.3V power, also Castle BEC’s have variable voltage so I can set it for 5.37V which is what the APM likes (JP1 on). The servos are variable from 5-6V, so 5.37V will be good. A bonus is that 2 BEC’s provides some redundancy.

program BEC (battery eliminator circuit): Castle 10A. With Castle Link USB programmer, makes it easy. 10g weight. I will do a future post on the Castlelink.

program ESC, set RPM governor. How-to coming soon.

The HMC5983. Much better compass than the 5883

this is a weird APM breakout board, from a Quanum nova. There is newer version of this board out now with different connectors

I think I got the wires in the corrects positions! who knows, there is no data for this APM. I had to follow the traces from the Arduino chip….we’ll see if it works when its powered up.